Employing Acoustic Emission for Monitoring Oil Film Regimes

Mhmod Hamel,Abdulmajid Addali,David Mba

doi:10.3390/lubricants1030061

Abstract

The major purpose of a gear lubricant is to provide adequate oil film thickness to reduce and prevent gear tooth surface failures. Real time monitoring for gear failures is important in order to predict and prevent unexpected failures which would have a negative impact on the efficiency, performance and safety of the gearbox. This paper presents experimental results on the influence of specific oil film thickness on Acoustic Emission (AE) activity for operational helical gears. Variation in film thickness during operations was achieved by spraying liquid nitrogen onto the rotating gear wheel. The experimental results demonstrated a clear relationship between the root mean square (r.m.s) value of the AE signal and the specific film thickness. The findings demonstrate the potential of Acoustic Emission technology to quantify lubrication regimes on operational gears.

Highlights

The rapid development and greatly increased competition in industry has enhanced the importance of gearboxes as vital parts in industrial equipment
It can be seen that at the start of the test the Acoustic Emission (AE) r.m.s level was constant for approximately 500 s at about
Results of this study indicate that the direct contact in dry conditions between the helical gears teeth was a significant source of AE energy, confirming that asperity contact is an essential source of AE

Summary

Introduction

The rapid development and greatly increased competition in industry has enhanced the importance of gearboxes as vital parts in industrial equipment. Gear failures are generally initiated in the tooth meshing zone. Monitoring for gear failures is important in order to predict and prevent surface failures at their earliest stages. The effectiveness and reliability of a gear depends on its lubricants and the oil film conditions at meshing. Specific oil film thickness (λ), which is the ratio between the oil film thickness (h) and the combined surface roughness (R) of the gears, play a major role in determining the Lubricants 2013, 1 operating life of gears. Maintaining a suitable value for λ helps ensuring good mechanical integrity [1,2]

Methods

Results

Conclusion